Buying and Connecting to a Cluster or Cluster (Performance-Enhanced) Instance

This section describes how to buy and connect to a GeminiDB Influx cluster or cluster (performance-enhanced) instance on the GeminiDB console.

• Cluster: One cluster consists of at least three nodes. Nodes can be added to a cluster, which is unsuitable to cope with the ever-growing data volume.
• (Recommended) Cluster (performance-enhanced): Compared with cluster instances, instances in a performance-enhanced cluster support a larger scale and higher read/write performance.

Each tenant can create a maximum of 50 GeminiDB Influx instances by default. To request a higher quota, choose Service Tickets > Create Service Ticket in the upper right corner of the console and contact the customer service.

• Step 1: Buying a Cluster or Cluster (Performance-Enhanced) Instance
• Step 2: Connecting to an Instance Through DAS

  For details about other connection methods, see Connecting to a GeminiDB Influx Instance.

1. Log in to the Huawei Cloud console.
2. In the service list, choose Databases > GeminiDB.
3. On the Instances page, click Buy DB Instance.
4. On the displayed page, select a billing mode, configure instance specifications, and click Next.

   The following parameters are for reference only. Select proper specifications as needed. Table 1 lists details about the parameters.

   Figure 1 Billing mode and basic information of a cluster instance
   
   Figure 2 Billing mode and basic information of a cluster (performance-enhanced) instance
   

   Parameter	Example Value	Description
   Billing Mode	Pay-per-use	Billing mode of an instance Yearly/Monthly is a prepaid billing mode in which you pay for resources before using it. Bills are settled based on the subscription period. The longer the subscription term, the bigger the discount. This mode is a good option for long-term stable services. Pay-per-use is a postpaid billing mode. You are billed based on how long you have actually used GeminiDB in 1-second increments and settled by the hour. This mode allows you to adjust resource usage easily. You neither need to prepare for resources in advance, nor end up with excessive or insufficient preset resources.
   Region	Select CN-Hong Kong.	The region where the tenant is located. It can be changed in the upper left corner. NOTE: To reduce network latency, select a region nearest from which you will access the instance. Instances deployed in different regions cannot communicate with each other through a private network. After you buy an instance, you cannot change its region. Cluster (performance-enhanced) instances are available only in the following region: AP-Bangkok
   DB Instance Name	User-defined	The instance name: Can be the same as an existing instance name. Can contain 4 to 64 characters and must start with a letter. It is case-sensitive and allows only letters, digits, hyphens (-), and underscores (_).
   Compatible API	InfluxDB	GeminiDB is compatible with mainstream NoSQL APIs, including Redis, DynamoDB, Cassandra, HBase, MongoDB, and InfluxDB. You can select GeminiDB APIs by following How Do I Select an API?
   Storage Type	Classic	Classic: classic architecture with decoupled storage and compute Cloud native: more flexible, new-gen version with support for more AZs NOTE: Cloud native storage is only available for cluster (performance-enhanced) instances. The way you use instances with classic or cloud native storage is similar. Cloud native storage supports more AZs. If both classic and cloud native are supported, you can select any of them.
   DB Instance Type	Cluster	One cluster consists of at least three nodes. Nodes can be added to a cluster, which is unsuitable to cope with the ever growing data volume. Compared with cluster instances, instances in a performance-enhanced cluster support a larger scale and higher read/write performance.
   DB Engine Version	1.8	If Storage Type is set to Classic, the version is fixed at 1.8. If Storage Type is set to Cloud native, the version is fixed at 1.7.
   AZ	AZ 1, AZ 2, and AZ 3	Availability zone where the instance is created. An AZ is a part of a region with its own independent power supplies and networks. AZs are physically isolated but can communicate with each other over a private network. Instances can be deployed in a single AZ or three AZs. To deploy instances in a single AZ, select one AZ. If you want to deploy your instance across AZs for disaster recovery, select three AZs. Nodes of the instance are evenly distributed across the three AZs.

   Figure 3 Storage and specifications
   

   

   

   Parameter	Example Value	Description
   Data Node Specifications	2U8GB	Data nodes provide read and write capabilities for time series databases. The specifications depend on configurations of the DFV shared resource pool and memory. Select specifications based on service requirements. For details about supported specifications, see Instance Specifications.
   Data Nodes	3	Select the number of data nodes based on service requirements. After an instance is created, you can add nodes. For details, see Adding Instance Nodes. Currently, a maximum of 12 nodes are supported. To add more, choose Service Tickets > Create Service Ticket in the upper right corner of the console and contact the customer service.
   Storage Space	100 GB	The storage is an integer and the minimum storage is 100 GB. You can add a minimum of 1 GB at a time.
   Purchase Cold Storage	No	Do not purchase cold storage. If you do not enable cold storage when creating an instance, you can enable it later based on service requirements. For details, see Enabling Cold Storage. NOTE: Cold storage cannot be disabled after being enabled.

   Figure 4 Network and database configurations
   

   Parameter	Example Value	Description
   VPC	default_vpc	Virtual private network where your instances are located. A VPC isolates networks for different services. You can select an existing VPC or create a VPC. NOTE: After a GeminiDB Influx instance is created, the VPC where the instance is deployed cannot be changed. To connect a GeminiDB Influx instance to an ECS over a private network, ensure they are in the same VPC. If they are not, create a VPC peering connection between them.
   Subnet	default_subnet	A subnet provides dedicated network resources that are logically isolated from other networks for security purposes.
   Security Group	default	A security group controls access between GeminiDB Influx instances and other services. Ensure that the security group you selected allows your client to access the instance. If no security group is available, the system creates one for you.
   Administrator Password	Configured based on the password policy	Password of the administrator account. The password: Can contain 8 to 32 characters. Can include uppercase letters, lowercase letters, digits, and any of the following special characters: ~!@#%^*-_=+? For security reasons, set a strong password. The system will verify the password strength. Keep your password secure. The system cannot retrieve it if it is lost.
   Parameter Template	Default-InfluxDB-1.8	A template of parameters for creating an instance. The template contains API configuration values that are applied to one or more instances. After an instance is created, you can modify its parameters to better meet your service requirements. For details, see Modifying Parameters of GeminiDB Influx Instances.
   Enterprise Project	default	This parameter is provided for enterprise users. An enterprise project groups cloud resources, so you can manage resources and members by project. The default project is default. Select an enterprise project from the drop-down list. For more information about enterprise projects, see Enterprise Management User Guide.

   Retain the default values for other parameters.

5. On the order confirmation page, check the instance information. If you need to modify the information, click Previous. If no modification is required, read and agree to the service agreement and click Submit.
6. Click Back to Instance Management to go to the instance list.
7. On the Instances page, view and manage the created instance.
   • Creating an instance takes about 5 to 9 minutes. During the process, the instance status displayed in the DB instance list is Creating.
   • After the instance is created, its status becomes Available.
   Figure 5 Available cluster instance
   
   Figure 6 Available cluster (performance-enhanced) instance